Polygonum is a genus annual or perennial herbs (ours) and vines. Stipules consist of a membranous sheath below each leaf (ocreae), the upper margins are often bristly.
Leaves usually alternate, simple (1-parted), margins smooth (entire).
Flowers small, petals and sepals alike (tepals). Ovary attached above tepals (superior).
Fruit consists of developed seed (achene), flat or 3-sided.